For the purpose of retaining security, the use of biometric information has become widespread for the authentication of people who enter a facility. Some personal devices such as personal computers and mobile phones are provided with biometric authentication functions such that the unauthorized use by other people will be prevented.
Biometric information is registered in advance in order to perform biometric authentication. However, users are not necessarily familiar with the registration process of biometric information, and some users may register biometric information of low quality. In such cases, a registrant may fail to be authorized in actual operation even though he/she is a genuine registrant. Moreover, an authentication error may occur due to the environment in which the biometric information is to be input being different from the environment at the time of the registration.
As a solution to the above problem, a technique is known in which registration threshold setting means capable of setting registration fingerprint quality is provided and the registration of fingerprint data below a certain level of quality is not allowed at the time of fingerprint registration. Furthermore, a technique is known in which the registered fingerprint data and the most recent successfully verified fingerprint data are stored and the influence due to the environment in which the biometric information is input is minimized by performing comprehensive evaluation for the fingerprint data to be verified, the registered fingerprint data, and the most recent successfully verified fingerprint data (for example, see Patent Document 1).
A technique is known in which the environment of when the biometric information was input is stored in association with the biometric information so as to reduce the variation in accuracy due to changes in the environment where the biometric information is input or deterioration over time, and authentication is performed by referring to the environment where the registered biometric information was input at the time of verification (for example, see Patent Document 2).
A technique is known in which partial images of a fingerprint are read by a fingerprint sensor and a fingerprint image is acquired from the read partial images for the purpose of minimizing a chip area in a fingerprint sensor where a semiconductor chip is used (for example, see Patent Document 3).